Governments and industry need to focus on what can be done now to cut aircraft emissions and not underestimate the technological challenges of developing new fuels, a senior figure at engine manufacturer Rolls Royce has warned.
Professor Herve Morvan, Rolls Royce chief of future platforms, told the Westminster Energy, Environment & Policy Conference on ‘Next steps for aviation decarbonisation’: “We need to recognise the importance of acting soon.
“Every element of carbon we put in the atmosphere just keeps accumulating. While it’s attractive to look for a perfect solution, if it comes late, it will have a limited impact by 2050. We need to consider what we can do now.”
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He insisted: “Efficiency is key, followed by steps towards drop-in fuels – sustainable aviation fuels (SAFs).”
Morvan argued: “For the foreseeable future, we’re reliant on gas turbine power [for flying]. So, continuing to invest in these technologies is key because driving efficiencies is the strongest tool we have available in reducing emissions.”
Rolls Royce is developing a new generation of gas turbine engines, UltraFan, which it says offers a 25% improvement on the emissions of its current generation of engines.
Morvan told the conference: “We’ve run all our engine families on SAF, either in ground tests or in flight [and] in collaboration with easyJet, we’ve run a modern gas turbine engine on 100%.”
He said it would be a mistake to view SAF and hydrogen as alternatives, explaining: “We’ll need significant amounts of hydrogen to ramp up SAF.”
However, he warned: “We shouldn’t underestimate the technical challenges. There is a step change [required]. Rolls Royce has looked at hydrogen since the 1970s. But integrating this into a product will take significant time. Investment in a [new] aircraft costs in the order of $30 billion-plus [and] it takes easily seven years for something to come through [to commercial use] based on known technology.
Morvan added: “It takes 20-27 years to renew a fleet [and] the shortest life of an airframe can be 16-18 years. Hydrogen is unlikely to be ‘the answer’ by 2050, which is why getting started on SAF is important. It’s something we can make happen relatively soon.”
He suggested decarbonising aviation had to be “part of a much-broader energy transition”, saying: “Decarbonising the grid to produce low cost, low carbon electricity and hydrogen is what we need.”
Concerns about SAF
There are “increasing concerns” about sustainable aviation fuel (SAF) and the UK government’s SAF mandate, details of which were confirmed in April.
That is according to Helena Bennett, head of climate policy at the European Climate Foundation, who told the Westminster conference: “There are issues with feedstock availability and scaling up the feedstocks required under the mandate. There are questions about how the ‘lifecycle emissions’ [of SAFs] are calculated.”
She noted: “There is no significant cap on HEFA [derived SAF] – from used cooking oil – when there is only a certain amount available globally [for] scaling up to the levels required under the SAF mandate.”
Bennett suggested this “calls into question how seriously the mandate will be implemented”.
She also asked: “How will all this be paid for? The vast majority of flights are taken by a small proportion of the population globally. Is it fair to ask the taxpayer to prop up the costs of SAF for travel primarily by frequent fliers?”
Bennett suggested: “This is an opportunity to start talking about aviation taxes – taxing private jets or introducing a frequent flyer levy.”
Bennett added: “The non-CO2 effects of flying [have] been discussed for so long, yet not a lot is being done.
“The London Heathrow to New York JFK route is one of the worst in the world for contrails [condensation trails]. We hear the science isn’t good enough, but getting started on this stuff would help.”